Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -rfc0b866a666b5e672eae00b42fe17405fa910843 -r08e5bebcd5947c30e8d9176211b16f822dfe475c
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision fc0b866a666b5e672eae00b42fe17405fa910843)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 08e5bebcd5947c30e8d9176211b16f822dfe475c)
@@ -1164,15 +1164,15 @@
         state = PRE_TREATMENT_RESERVOIR_MGMT_REQUEST_RESERVOIR_SWITCH_STATE;
 
         // Start tracking flush cycles, flushComplete => don't drain again, this completes the final fill.
-        if ( FALSE == reservoirStatus[ activeReservoir ].flushComplete )
+        if ( FALSE == reservoirStatus[ inactiveReservoir ].flushComplete )
         {
-            if ( 0 < reservoirStatus[ activeReservoir ].flushCount )
+            if ( reservoirStatus[ inactiveReservoir ].flushCount > 0 )
             {
-                reservoirStatus[ activeReservoir ].flushCount -= 1;
+                reservoirStatus[ inactiveReservoir ].flushCount -= 1;
             }
-            if ( 0 == reservoirStatus[ activeReservoir ].flushCount )
+            if ( 0 == reservoirStatus[ inactiveReservoir ].flushCount )
             {
-                reservoirStatus[ activeReservoir ].flushComplete = TRUE;
+                reservoirStatus[ inactiveReservoir ].flushComplete = TRUE;
             }
         }